diff --git a/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleCommandLineTests.cs b/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleCommandLineTests.cs
index b447be0bfe..9ea19fbeb0 100644
--- a/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleCommandLineTests.cs
+++ b/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleCommandLineTests.cs
@@ -23,7 +23,7 @@ namespace UnitTesting.Tests.NUnit
 		public void SetUp()
 		{
 			project = new MockCSharpProject();
-			project.FileName = @"C:\Projects\MyTests\MyTests.csproj";
+			project.FileName = FileName.Create(@"C:\Projects\MyTests\MyTests.csproj");
 			project.AssemblyName = "MyTests";
 			project.OutputType = OutputType.Library;
 			project.SetProperty("OutputPath", null);
diff --git a/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleExeSelectedTestFixture.cs b/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleExeSelectedTestFixture.cs
index 798d195be4..ec5efc8e6b 100644
--- a/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleExeSelectedTestFixture.cs
+++ b/src/AddIns/Analysis/UnitTesting/Test/NUnit/NUnitConsoleExeSelectedTestFixture.cs
@@ -125,7 +125,7 @@ namespace UnitTesting.Tests.NUnit
 		[Test]
 		public void NotMSBuildBasedProject()
 		{
-			MissingProject project = new MissingProject(@"C:\Projects\Test.proj", "Test");
+			MissingProject project = new MissingProject(FileName.Create(@"C:\Projects\Test.proj"), "Test");
 			ITestProject testProject = new NUnitTestProject(project);
 			NUnitConsoleApplication app = new NUnitConsoleApplication(new[] { testProject });
 			
diff --git a/src/AddIns/Analysis/UnitTesting/Test/Service/TestFrameworkDescriptorTests.cs b/src/AddIns/Analysis/UnitTesting/Test/Service/TestFrameworkDescriptorTests.cs
index c744c096ec..5653ac4c43 100644
--- a/src/AddIns/Analysis/UnitTesting/Test/Service/TestFrameworkDescriptorTests.cs
+++ b/src/AddIns/Analysis/UnitTesting/Test/Service/TestFrameworkDescriptorTests.cs
@@ -35,7 +35,7 @@ namespace UnitTesting.Tests.Service
 		MockCSharpProject CreateCSharpProjectNotSupportedByTestFramework()
 		{
 			var project = new MockCSharpProject();
-			project.FileName = @"d:\projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"d:\projects\MyProject\MyProject.csproj");
 			fakeTestFramework = MockRepository.GenerateStrictMock<ITestFramework>();
 			fakeTestFramework.Stub(f => f.IsTestProject(project)).Return(false);
 			return project;
@@ -52,7 +52,7 @@ namespace UnitTesting.Tests.Service
 		MockCSharpProject CreateVisualBasicProjectSupportedByTestFramework()
 		{
 			MockCSharpProject project = CreateCSharpProjectSupportedByTestFramework();
-			project.FileName = @"d:\projects\MyProject\MyProject.vbproj";
+			project.FileName = FileName.Create(@"d:\projects\MyProject\MyProject.vbproj");
 			return project;
 		}
 		
@@ -167,7 +167,7 @@ namespace UnitTesting.Tests.Service
 		{
 			CreateTestFrameworkDescriptorToSupportProjectFileExtensions(".csproj");
 			MockCSharpProject project = CreateCSharpProjectSupportedByTestFramework();
-			project.FileName = @"d:\projects\MyProject\MyProject.CSPROJ";
+			project.FileName = FileName.Create(@"d:\projects\MyProject\MyProject.CSPROJ");
 			
 			bool supported = descriptor.IsSupportedProject(project);
 			
diff --git a/src/AddIns/Analysis/UnitTesting/Test/Utils/MockCSharpProject.cs b/src/AddIns/Analysis/UnitTesting/Test/Utils/MockCSharpProject.cs
index e076d2d762..3e53382507 100644
--- a/src/AddIns/Analysis/UnitTesting/Test/Utils/MockCSharpProject.cs
+++ b/src/AddIns/Analysis/UnitTesting/Test/Utils/MockCSharpProject.cs
@@ -2,6 +2,7 @@
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
 using System;
+using ICSharpCode.Core;
 using ICSharpCode.NRefactory.TypeSystem;
 using ICSharpCode.NRefactory.TypeSystem.Implementation;
 using ICSharpCode.NRefactory.CSharp;
@@ -26,7 +27,7 @@ namespace UnitTesting.Tests.Utils
 			       	ProjectName = name,
 			       	Platform = "x86",
 			       	TargetFramework = TargetFramework.Net40Client,
-			       	OutputProjectFileName = "c:\\projects\\" + name + "\\" + name + ".csproj"
+			       	OutputProjectFileName = FileName.Create("c:\\projects\\" + name + "\\" + name + ".csproj")
 			       })
 		{
 			OutputType = OutputType.Library;
diff --git a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/CSharpSemanticHighlighter.cs b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/CSharpSemanticHighlighter.cs
index bcfe44d06c..ff70ebc12e 100644
--- a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/CSharpSemanticHighlighter.cs
+++ b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/CSharpSemanticHighlighter.cs
@@ -26,7 +26,7 @@ namespace CSharpBinding
 	/// <summary>
 	/// Semantic highlighting for C#.
 	/// </summary>
-	public class CSharpSemanticHighlighter : DepthFirstAstVisitor, IHighlighter, IDisposable
+	public class CSharpSemanticHighlighter : DepthFirstAstVisitor, IHighlighter
 	{
 		readonly IDocument document;
 		readonly HighlightingColor defaultTextColor;
diff --git a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/CSharpSymbolSearch.cs b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/CSharpSymbolSearch.cs
index 8dafa88a93..da02599a73 100644
--- a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/CSharpSymbolSearch.cs
+++ b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/CSharpSymbolSearch.cs
@@ -117,6 +117,9 @@ namespace CSharpBinding
 					var defaultTextColor = highlighter != null ? highlighter.DefaultTextColor : null;
 					results.Add(new Reference(region, result, offset, length, builder, defaultTextColor));
 				}, cancellationToken);
+			if (highlighter != null) {
+				highlighter.Dispose();
+			}
 			if (results.Count > 0)
 				callback(new SearchedFile(fileName, results));
 		}
diff --git a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/Parser.cs b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/Parser.cs
index 214e7d5e9f..4c565fa075 100644
--- a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/Parser.cs
+++ b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/Parser.cs
@@ -153,6 +153,10 @@ namespace CSharpBinding.Parser
 					var defaultTextColor = highlighter != null ? highlighter.DefaultTextColor : null;
 					callback(new Reference(region, result, offset, length, builder, defaultTextColor));
 				}, cancellationToken);
+			
+			if (highlighter != null) {
+				highlighter.Dispose();
+			}
 		}
 		
 		static readonly Lazy<IAssemblyReference[]> defaultReferences = new Lazy<IAssemblyReference[]>(
diff --git a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Refactoring/SearchForIssuesCommand.cs b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Refactoring/SearchForIssuesCommand.cs
index 8efd1dd0fd..e0cb71a1db 100644
--- a/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Refactoring/SearchForIssuesCommand.cs
+++ b/src/AddIns/BackendBindings/CSharpBinding/Project/Src/Refactoring/SearchForIssuesCommand.cs
@@ -168,6 +168,9 @@ namespace CSharpBinding.Refactoring
 					results.Add(SearchResultMatch.Create(document, issue.Start, issue.End, highlighter));
 				}
 			}
+			if (highlighter != null) {
+				highlighter.Dispose();
+			}
 			if (results.Count > 0)
 				return new SearchedFile(fileName, results);
 			else
@@ -243,8 +246,9 @@ namespace CSharpBinding.Refactoring
 				}
 			}
 			if (allIssues.Count > 0) {
-				var highlighter = SD.EditorControlService.CreateHighlighter(document);
-				return allIssues.Select(issue => SearchResultMatch.Create(document, issue.Start, issue.End, highlighter));
+				using (var highlighter = SD.EditorControlService.CreateHighlighter(document)) {
+					return allIssues.Select(issue => SearchResultMatch.Create(document, issue.Start, issue.End, highlighter)).ToList();
+				}
 			} else {
 				return Enumerable.Empty<SearchResultMatch>();
 			}
diff --git a/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlSymbolSearch.cs b/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlSymbolSearch.cs
index 7779f3f8de..44701f868f 100644
--- a/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlSymbolSearch.cs
+++ b/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlSymbolSearch.cs
@@ -104,6 +104,9 @@ namespace ICSharpCode.XamlBinding
 				}
 				offset = textSource.IndexOf(entity.Name, offset + length, textSource.TextLength - offset - length, StringComparison.OrdinalIgnoreCase);
 			} while (offset > 0);
+			if (highlighter != null) {
+				highlighter.Dispose();
+			}
 			callback(new SearchedFile(fileName, results));
 		}
 	}
diff --git a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs
index 1ed8bc559f..88459214a9 100644
--- a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs
+++ b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs
@@ -134,6 +134,8 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		
 		void UpdateSyntaxHighlighting(FileName fileName)
 		{
+			var oldHighlighter = primaryTextEditor.GetService<IHighlighter>();
+			
 			var highlighting = HighlightingManager.Instance.GetDefinitionByExtension(Path.GetExtension(fileName));
 			var highlighter = SD.EditorControlService.CreateHighlighter(document);
 
@@ -148,6 +150,11 @@ namespace ICSharpCode.AvalonEdit.AddIn
 				secondaryTextEditor.TextArea.TextView.LineTransformers.Insert(0, new HighlightingColorizer(highlighter));
 				secondaryTextEditor.UpdateCustomizedHighlighting();
 			}
+			// Dispose the old highlighter; necessary to avoid memory leaks as
+			// semantic highlighters might attach to global parser events.
+			if (oldHighlighter != null) {
+				oldHighlighter.Dispose();
+			}
 		}
 		
 		public void Redraw(ISegment segment, DispatcherPriority priority)
@@ -263,6 +270,9 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			foreach (var d in textEditor.TextArea.LeftMargins.OfType<IDisposable>())
 				d.Dispose();
 			textEditor.TextArea.GetRequiredService<EnhancedScrollBar>().Dispose();
+			var highlighter = textEditor.TextArea.GetService<IHighlighter>();
+			if (highlighter != null)
+				highlighter.Dispose();
 			textEditor.Dispose();
 		}
 		
diff --git a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CustomizableHighlightingColorizer.cs b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CustomizableHighlightingColorizer.cs
index 828411176e..e07166ad6d 100644
--- a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CustomizableHighlightingColorizer.cs
+++ b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CustomizableHighlightingColorizer.cs
@@ -126,6 +126,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		readonly IHighlightingDefinition highlightingDefinition;
 		readonly IEnumerable<CustomizedHighlightingColor> customizations;
 		
+		[ObsoleteAttribute("Use a normal HighlightingColorizer with a CustomizingHighlighter instead")]
 		public CustomizableHighlightingColorizer(IHighlightingDefinition highlightingDefinition, IEnumerable<CustomizedHighlightingColor> customizations)
 			: base(highlightingDefinition)
 		{
@@ -152,7 +153,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			return new CustomizingHighlighter(textView, customizations, highlightingDefinition, base.CreateHighlighter(textView, document));
 		}
 		
-		internal sealed class CustomizingHighlighter : IHighlighter
+		internal sealed class CustomizingHighlighter : IHighlighter, IDisposable
 		{
 			readonly TextView textView;
 			readonly IEnumerable<CustomizedHighlightingColor> customizations;
@@ -296,6 +297,11 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			{
 				baseHighlighter.EndHighlighting();
 			}
+			
+			public void Dispose()
+			{
+				baseHighlighter.Dispose();
+			}
 		}
 		
 		internal static HighlightingColor CustomizeColor(HighlightingColor color, IEnumerable<CustomizedHighlightingColor> customizations)
diff --git a/src/AddIns/Misc/SearchAndReplace/Project/Engine/SearchManager.cs b/src/AddIns/Misc/SearchAndReplace/Project/Engine/SearchManager.cs
index 025af9bf6b..da6afa5622 100644
--- a/src/AddIns/Misc/SearchAndReplace/Project/Engine/SearchManager.cs
+++ b/src/AddIns/Misc/SearchAndReplace/Project/Engine/SearchManager.cs
@@ -218,6 +218,9 @@ namespace SearchAndReplace
 					var defaultTextColor = highlighter != null ? highlighter.DefaultTextColor : null;
 					results.Add(new AvalonEditSearchResultMatch(fileName, start, end, result.Offset, result.Length, builder, defaultTextColor, result));
 				}
+				if (highlighter != null) {
+					highlighter.Dispose();
+				}
 				if (results.Count > 0)
 					return new SearchedFile(fileName, results);
 				else
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/DocumentHighlighter.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/DocumentHighlighter.cs
index c2e3c63ff1..ecdbf4d3f9 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/DocumentHighlighter.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/DocumentHighlighter.cs
@@ -29,6 +29,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		readonly CompressingTreeList<bool> isValid = new CompressingTreeList<bool>((a, b) => a == b);
 		readonly IDocument document;
 		readonly IHighlightingDefinition definition;
+		readonly WeakLineTracker weakLineTracker;
 		bool isHighlighting;
 		
 		/// <summary>
@@ -49,7 +50,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 				throw new ArgumentNullException("definition");
 			this.document = document;
 			this.definition = definition;
-			WeakLineTracker.Register(document, this);
+			weakLineTracker = WeakLineTracker.Register(document, this);
 			InvalidateHighlighting();
 		}
 		
@@ -67,6 +68,15 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 			InvalidateHighlighting();
 		}
 		
+		/// <summary>
+		/// Disposes the document highlighter.
+		/// </summary>
+		public void Dispose()
+		{
+			if (weakLineTracker != null)
+				weakLineTracker.Deregister();
+		}
+		
 		void ILineTracker.BeforeRemoveLine(DocumentLine line)
 		{
 			CheckIsHighlighting();
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/HighlightingColorizer.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/HighlightingColorizer.cs
index 0e78b46eaf..ff8223de13 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/HighlightingColorizer.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/HighlightingColorizer.cs
@@ -24,7 +24,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		/// <summary>
 		/// Creates a new HighlightingColorizer instance.
 		/// </summary>
-		/// <param name="ruleSet">The root highlighting rule set.</param>
+		/// <param name="definition">The highlighting definition.</param>
 		public HighlightingColorizer(IHighlightingDefinition definition)
 		{
 			if (definition == null)
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/IHighlighter.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/IHighlighter.cs
index 858a9abdad..70c37ef26a 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/IHighlighter.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/IHighlighter.cs
@@ -11,7 +11,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 	/// Represents a highlighted document.
 	/// </summary>
 	/// <remarks>This interface is used by the <see cref="HighlightingColorizer"/> to register the highlighter as a TextView service.</remarks>
-	public interface IHighlighter
+	public interface IHighlighter : IDisposable
 	{
 		/// <summary>
 		/// Gets the underlying text document.
@@ -183,6 +183,13 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 			}
 			return null;
 		}
+		
+		public void Dispose()
+		{
+			foreach (var h in nestedHighlighters) {
+				h.Dispose();
+			}
+		}
 	}
 	
 	/// <summary>
diff --git a/src/Main/Base/Project/Parser/ProjectContentContainer.cs b/src/Main/Base/Project/Parser/ProjectContentContainer.cs
index e8d4b9538d..85672926ee 100644
--- a/src/Main/Base/Project/Parser/ProjectContentContainer.cs
+++ b/src/Main/Base/Project/Parser/ProjectContentContainer.cs
@@ -55,7 +55,7 @@ namespace ICSharpCode.SharpDevelop.Parser
 			this.project = project;
 			this.projectContent = initialProjectContent.SetAssemblyName(project.AssemblyName).SetLocation(project.OutputAssemblyFullPath);
 			
-			this.cacheFileName = GetCacheFileName(FileName.Create(project.FileName));
+			this.cacheFileName = GetCacheFileName(project.FileName);
 			
 			ProjectService.ProjectItemAdded += OnProjectItemAdded;
 			ProjectService.ProjectItemRemoved += OnProjectItemRemoved;
diff --git a/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/Commands/SolutionNodeCommands.cs b/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/Commands/SolutionNodeCommands.cs
index 15ed121078..291da236d1 100644
--- a/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/Commands/SolutionNodeCommands.cs
+++ b/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/Commands/SolutionNodeCommands.cs
@@ -28,7 +28,7 @@ namespace ICSharpCode.SharpDevelop.Project.Commands
 							MessageService.ShowError("No project has been created, there is nothing to add.");
 							return;
 						}
-						AddExitingProjectToSolution.AddProject(solutionFolderNode, npdlg.NewProjectLocation);
+						AddExitingProjectToSolution.AddProject(solutionFolderNode, FileName.Create(npdlg.NewProjectLocation));
 						ProjectService.SaveSolution();
 					}
 				}
@@ -64,7 +64,7 @@ namespace ICSharpCode.SharpDevelop.Project.Commands
 	
 	public class AddExitingProjectToSolution : AbstractMenuCommand
 	{
-		public static void AddProject(ISolutionFolderNode solutionFolderNode, string fileName)
+		public static void AddProject(ISolutionFolderNode solutionFolderNode, FileName fileName)
 		{
 			if (solutionFolderNode == null)
 				throw new ArgumentNullException("solutionFolderNode");
@@ -97,7 +97,7 @@ namespace ICSharpCode.SharpDevelop.Project.Commands
 					fdiag.InitialDirectory = AddNewProjectToSolution.GetInitialDirectorySuggestion(solutionFolderNode);
 					if (fdiag.ShowDialog(ICSharpCode.SharpDevelop.Gui.WorkbenchSingleton.MainWin32Window) == DialogResult.OK) {
 						foreach (string fileName in fdiag.FileNames) {
-							AddProject(solutionFolderNode, fileName);
+							AddProject(solutionFolderNode, FileName.Create(fileName));
 						}
 						ProjectService.SaveSolution();
 					}
diff --git a/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/TreeNodes/ProjectNode.cs b/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/TreeNodes/ProjectNode.cs
index db91a95e95..23e496e46a 100644
--- a/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/TreeNodes/ProjectNode.cs
+++ b/src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/TreeNodes/ProjectNode.cs
@@ -220,7 +220,7 @@ namespace ICSharpCode.SharpDevelop.Project
 					}
 				}
 			}
-			project.FileName = newFileName;
+			project.FileName = FileName.Create(newFileName);
 			project.Name = newName;
 			ProjectService.SaveSolution();
 		}
diff --git a/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectCreateInformation.cs b/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectCreateInformation.cs
index d9a992236d..853339116e 100644
--- a/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectCreateInformation.cs
+++ b/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectCreateInformation.cs
@@ -6,6 +6,7 @@ using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.IO;
 
+using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop.Project;
 
 namespace ICSharpCode.SharpDevelop.Internal.Templates
@@ -35,7 +36,7 @@ namespace ICSharpCode.SharpDevelop.Internal.Templates
 			get { return createdProjects.AsReadOnly(); }
 		}
 		
-		public string OutputProjectFileName { get; set; }
+		public FileName OutputProjectFileName { get; set; }
 		public string Platform { get; set; }
 		public string ProjectName { get; set; }
 		public string SolutionName { get; set; }
diff --git a/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectDescriptor.cs b/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectDescriptor.cs
index 230399cf8c..af2d18b7c4 100644
--- a/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectDescriptor.cs
+++ b/src/Main/Base/Project/Src/Internal/Templates/Project/ProjectDescriptor.cs
@@ -323,7 +323,7 @@ namespace ICSharpCode.SharpDevelop.Internal.Templates
 					}
 				}
 				
-				projectCreateInformation.OutputProjectFileName = projectLocation;
+				projectCreateInformation.OutputProjectFileName = FileName.Create(projectLocation);
 				projectCreateInformation.RootNamespace = standardNamespace.ToString();
 				projectCreateInformation.ProjectName = newProjectName;
 				if (!string.IsNullOrEmpty(defaultPlatform))
diff --git a/src/Main/Base/Project/Src/Project/AbstractProject.cs b/src/Main/Base/Project/Src/Project/AbstractProject.cs
index a5717538a4..3c290adb61 100644
--- a/src/Main/Base/Project/Src/Project/AbstractProject.cs
+++ b/src/Main/Base/Project/Src/Project/AbstractProject.cs
@@ -86,7 +86,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		#endregion
 		
 		#region Filename / Directory
-		volatile string fileName;
+		volatile FileName fileName;
 		string cachedDirectoryName;
 		protected IProjectChangeWatcher watcher;
 		
@@ -97,9 +97,9 @@ namespace ICSharpCode.SharpDevelop.Project
 		/// Only the getter is thread-safe.
 		/// </summary>
 		[ReadOnly(true)]
-		public string FileName {
+		public FileName FileName {
 			get {
-				return fileName ?? "";
+				return fileName;
 			}
 			set {
 				if (value == null)
diff --git a/src/Main/Base/Project/Src/Project/Converter/LanguageConverter.cs b/src/Main/Base/Project/Src/Project/Converter/LanguageConverter.cs
index c5ab5e58bc..0fd443bbee 100644
--- a/src/Main/Base/Project/Src/Project/Converter/LanguageConverter.cs
+++ b/src/Main/Base/Project/Src/Project/Converter/LanguageConverter.cs
@@ -39,7 +39,7 @@ namespace ICSharpCode.SharpDevelop.Project.Converter
 			if (descriptor == null || descriptor.Binding == null)
 				throw new InvalidOperationException("Cannot get Language Binding for " + TargetLanguageName);
 			
-			info.OutputProjectFileName = FileUtility.NormalizePath(Path.Combine(targetProjectDirectory, info.ProjectName + descriptor.ProjectFileExtension));
+			info.OutputProjectFileName = FileName.Create(Path.Combine(targetProjectDirectory, info.ProjectName + descriptor.ProjectFileExtension));
 			
 			return descriptor.Binding.CreateProject(info);
 		}
diff --git a/src/Main/Base/Project/Src/Project/IProject.cs b/src/Main/Base/Project/Src/Project/IProject.cs
index 85d99cdf82..d4e748a79e 100644
--- a/src/Main/Base/Project/Src/Project/IProject.cs
+++ b/src/Main/Base/Project/Src/Project/IProject.cs
@@ -69,7 +69,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		/// 
 		/// Only the getter is thread-safe.
 		/// </summary>
-		string FileName {
+		FileName FileName {
 			get;
 			set;
 		}
diff --git a/src/Main/Base/Project/Src/Project/Items/ProjectReferenceProjectItem.cs b/src/Main/Base/Project/Src/Project/Items/ProjectReferenceProjectItem.cs
index 02ac994d5c..eb536a4a38 100644
--- a/src/Main/Base/Project/Src/Project/Items/ProjectReferenceProjectItem.cs
+++ b/src/Main/Base/Project/Src/Project/Items/ProjectReferenceProjectItem.cs
@@ -16,8 +16,9 @@ namespace ICSharpCode.SharpDevelop.Project
 		[Browsable(false)]
 		public IProject ReferencedProject {
 			get {
-				// must be thread-safe because it's used by LoadSolutionProjectsThread
-				return ProjectService.GetProject(this.FileName);
+				// must be thread-safe because it's used by LoadSolutionProjectsThread,
+				// and by IAssemblyReference.Resolve()
+				return ProjectService.GetProject(Core.FileName.Create(this.FileName));
 			}
 		}
 		
diff --git a/src/Main/Base/Project/Src/Project/MSBuildFileProject.cs b/src/Main/Base/Project/Src/Project/MSBuildFileProject.cs
index 8885890d30..3270124b35 100644
--- a/src/Main/Base/Project/Src/Project/MSBuildFileProject.cs
+++ b/src/Main/Base/Project/Src/Project/MSBuildFileProject.cs
@@ -13,7 +13,7 @@ namespace ICSharpCode.SharpDevelop.Project
 	/// </summary>
 	public class MSBuildFileProject : AbstractProject
 	{
-		public MSBuildFileProject(string fileName, string title)
+		public MSBuildFileProject(FileName fileName, string title)
 		{
 			Name     = title;
 			FileName = fileName;
diff --git a/src/Main/Base/Project/Src/Project/MissingProject.cs b/src/Main/Base/Project/Src/Project/MissingProject.cs
index 1e7bf5f76c..089b219a6b 100644
--- a/src/Main/Base/Project/Src/Project/MissingProject.cs
+++ b/src/Main/Base/Project/Src/Project/MissingProject.cs
@@ -2,12 +2,13 @@
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
 using System;
+using ICSharpCode.Core;
 
 namespace ICSharpCode.SharpDevelop.Project
 {
 	public class MissingProject : AbstractProject
 	{
-		public MissingProject(string fileName, string title)
+		public MissingProject(FileName fileName, string title)
 		{
 			Name     = title;
 			FileName = fileName;
diff --git a/src/Main/Base/Project/Src/Project/ProjectLoadInformation.cs b/src/Main/Base/Project/Src/Project/ProjectLoadInformation.cs
index e4f1de8a1a..2790352fc5 100644
--- a/src/Main/Base/Project/Src/Project/ProjectLoadInformation.cs
+++ b/src/Main/Base/Project/Src/Project/ProjectLoadInformation.cs
@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using ICSharpCode.Core;
 
 namespace ICSharpCode.SharpDevelop.Project
 {
@@ -12,7 +13,7 @@ namespace ICSharpCode.SharpDevelop.Project
 	public class ProjectLoadInformation
 	{
 		public Solution ParentSolution { get; private set; }
-		public string FileName { get; private set; }
+		public FileName FileName { get; private set; }
 		public string Configuration { get; internal set; }
 		public string Platform { get; internal set; }
 		public string ProjectName { get; private set; }
@@ -44,7 +45,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			}
 		}
 		
-		public ProjectLoadInformation(Solution parentSolution, string fileName, string projectName)
+		public ProjectLoadInformation(Solution parentSolution, FileName fileName, string projectName)
 		{
 			if (parentSolution == null)
 				throw new ArgumentNullException("parentSolution");
diff --git a/src/Main/Base/Project/Src/Project/Solution/Solution.cs b/src/Main/Base/Project/Src/Project/Solution/Solution.cs
index 82b9c5ea23..2c4b29f5ed 100644
--- a/src/Main/Base/Project/Src/Project/Solution/Solution.cs
+++ b/src/Main/Base/Project/Src/Project/Solution/Solution.cs
@@ -544,7 +544,7 @@ namespace ICSharpCode.SharpDevelop.Project
 						SolutionFolder newFolder = SolutionFolder.ReadFolder(sr, title, location, guid);
 						newSolution.AddFolder(newFolder);
 					} else {
-						ProjectLoadInformation loadInfo = new ProjectLoadInformation(newSolution, location, title);
+						ProjectLoadInformation loadInfo = new ProjectLoadInformation(newSolution, Core.FileName.Create(location), title);
 						loadInfo.TypeGuid = projectGuid;
 						loadInfo.Guid = guid;
 						projectsToLoad.Add(loadInfo);
diff --git a/src/Main/Base/Project/Src/Project/UnknownProject.cs b/src/Main/Base/Project/Src/Project/UnknownProject.cs
index ddb1f71da8..4f56b4abcc 100644
--- a/src/Main/Base/Project/Src/Project/UnknownProject.cs
+++ b/src/Main/Base/Project/Src/Project/UnknownProject.cs
@@ -27,7 +27,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			MessageService.ShowError("Error loading " + this.FileName + ":\n" + warningText);
 		}
 		
-		public UnknownProject(string fileName, string title, string warningText, bool displayWarningToUser)
+		public UnknownProject(FileName fileName, string title, string warningText, bool displayWarningToUser)
 			: this(fileName, title)
 		{
 			this.warningText = warningText;
@@ -36,7 +36,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			}
 		}
 		
-		public UnknownProject(string fileName, string title)
+		public UnknownProject(FileName fileName, string title)
 		{
 			Name     = title;
 			FileName = fileName;
diff --git a/src/Main/Base/Project/Src/Services/ProjectBinding/ProjectBindingService.cs b/src/Main/Base/Project/Src/Services/ProjectBinding/ProjectBindingService.cs
index 96fba9c10b..722bd31013 100644
--- a/src/Main/Base/Project/Src/Services/ProjectBinding/ProjectBindingService.cs
+++ b/src/Main/Base/Project/Src/Services/ProjectBinding/ProjectBindingService.cs
@@ -89,7 +89,7 @@ namespace ICSharpCode.SharpDevelop
 			if (loadInformation == null)
 				throw new ArgumentNullException("loadInformation");
 			
-			string location = FileUtility.NormalizePath(loadInformation.FileName);
+			var location = loadInformation.FileName;
 			string title = loadInformation.ProjectName;
 			IProgressMonitor progressMonitor = loadInformation.ProgressMonitor;
 			
diff --git a/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs b/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs
index adbbfc93e2..bcba4f591a 100644
--- a/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs
+++ b/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs
@@ -52,13 +52,13 @@ namespace ICSharpCode.SharpDevelop.Project
 		/// <summary>
 		/// Gets an open project by the name of the project file.
 		/// </summary>
-		public static IProject GetProject(string projectFilename)
+		public static IProject GetProject(FileName projectFilename)
 		{
 			Solution sln = openSolution;
 			if (sln == null)
 				return null;
 			foreach (IProject project in sln.Projects) {
-				if (FileUtility.IsEqualFileName(project.FileName, projectFilename)) {
+				if (project.FileName == projectFilename) {
 					return project;
 				}
 			}
@@ -376,7 +376,7 @@ namespace ICSharpCode.SharpDevelop.Project
 						                                          "${res:Global.IgnoreButtonText}");
 						if (res == 0) {
 							// Add project to solution
-							Commands.AddExitingProjectToSolution.AddProject((ISolutionFolderNode)ProjectBrowserPad.Instance.SolutionNode, fileName);
+							Commands.AddExitingProjectToSolution.AddProject((ISolutionFolderNode)ProjectBrowserPad.Instance.SolutionNode, FileName.Create(fileName));
 							SaveSolution();
 							return;
 						} else if (res == 1) {
@@ -402,7 +402,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			IProjectBinding binding = ProjectBindingService.GetBindingPerProjectFile(fileName);
 			IProject project;
 			if (binding != null) {
-				project = ProjectBindingService.LoadProject(new ProjectLoadInformation(solution, fileName, solution.Name));
+				project = ProjectBindingService.LoadProject(new ProjectLoadInformation(solution, FileName.Create(fileName), solution.Name));
 				if (project is UnknownProject) {
 					if (((UnknownProject)project).WarningDisplayedToUser == false) {
 						((UnknownProject)project).ShowWarningMessageBox();
diff --git a/src/Main/Base/Project/Src/Services/RefactoringService/FindReferencesAndRenameHelper.cs b/src/Main/Base/Project/Src/Services/RefactoringService/FindReferencesAndRenameHelper.cs
index 8430d239a5..40c23dd6db 100644
--- a/src/Main/Base/Project/Src/Services/RefactoringService/FindReferencesAndRenameHelper.cs
+++ b/src/Main/Base/Project/Src/Services/RefactoringService/FindReferencesAndRenameHelper.cs
@@ -347,6 +347,9 @@ namespace ICSharpCode.SharpDevelop.Refactoring
 			IHighlighter highlighter = null;
 			foreach (Reference r in list) {
 				if (document == null || fileName != r.FileName) {
+					if (highlighter != null) {
+						highlighter.Dispose();
+					}
 					fileName = r.FileName;
 					buffer = SD.FileService.GetFileContent(r.FileName);
 					document = new ReadOnlyDocument(buffer, r.FileName);
@@ -361,6 +364,9 @@ namespace ICSharpCode.SharpDevelop.Refactoring
 				SearchResultMatch res = new SearchResultMatch(fileName, start, end, startOffset, endOffset - startOffset, builder, defaultTextColor);
 				results.Add(res);
 			}
+			if (highlighter != null) {
+				highlighter.Dispose();
+			}
 			SearchResultsPad.Instance.ShowSearchResults(title, results);
 			SearchResultsPad.Instance.BringToFront();
 		}
diff --git a/src/Main/Base/Test/ServiceReferences/DirectoryNodeFactoryTests.cs b/src/Main/Base/Test/ServiceReferences/DirectoryNodeFactoryTests.cs
index c97ab25586..2c407f2f97 100644
--- a/src/Main/Base/Test/ServiceReferences/DirectoryNodeFactoryTests.cs
+++ b/src/Main/Base/Test/ServiceReferences/DirectoryNodeFactoryTests.cs
@@ -88,7 +88,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void CreateDirectoryNode_ProjectHasServiceReferencesItemAndDirectoryMatchesServiceReferencesPath_CreatesServiceReferencesFolderNode()
 		{
 			CreateProject();
-			project.FileName = @"d:\projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"d:\projects\MyProject\MyProject.csproj");
 			ServiceReferencesProjectItem projectItem = AddWCFMetadataProjectItemToProject();
 			projectItem.Include = @"Service References\";
 			
@@ -103,7 +103,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void CreateDirectoryNode_FileProjectItemThatEndsWithForwardSlash_DirectoryNodeCreatedWithForwardSlashRemoved()
 		{
 			CreateProject();
-			project.FileName = @"d:\projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"d:\projects\MyProject\MyProject.csproj");
 			FileProjectItem projectItem = CreateFileProjectItem(@"MyFolder/");
 			
 			DirectoryNode node = DirectoryNodeFactory.CreateDirectoryNode(projectItem, FileNodeStatus.None);
@@ -115,7 +115,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void CreateDirectoryNode_FileProjectItemThatEndsWithBackSlash_DirectoryNodeCreatedWithBackSlashRemoved()
 		{
 			CreateProject();
-			project.FileName = @"d:\projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"d:\projects\MyProject\MyProject.csproj");
 			FileProjectItem projectItem = CreateFileProjectItem(@"MyFolder\");
 			
 			DirectoryNode node = DirectoryNodeFactory.CreateDirectoryNode(projectItem, FileNodeStatus.None);
diff --git a/src/Main/Base/Test/ServiceReferences/ProjectWithServiceReferencesTests.cs b/src/Main/Base/Test/ServiceReferences/ProjectWithServiceReferencesTests.cs
index 2c2f1f2a54..80926a0d1b 100644
--- a/src/Main/Base/Test/ServiceReferences/ProjectWithServiceReferencesTests.cs
+++ b/src/Main/Base/Test/ServiceReferences/ProjectWithServiceReferencesTests.cs
@@ -6,6 +6,7 @@ using System.CodeDom.Compiler;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop.Gui.Dialogs.ReferenceDialog.ServiceReference;
 using ICSharpCode.SharpDevelop.Project;
 using ICSharpCode.SharpDevelop.Tests.WebReferences;
@@ -335,7 +336,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void AddAppConfigFile_ProjectHasNoAppConfig_ProjectItemAddedToProjectForAppConfig()
 		{
 			CreateProjectWithMSBuildProject();
-			msbuildProject.FileName = @"d:\projects\MyProject\myproject.csproj";
+			msbuildProject.FileName = FileName.Create(@"d:\projects\MyProject\myproject.csproj");
 			
 			project.AddAppConfigFile();
 			
@@ -391,7 +392,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void GetAppConfigFileName_ProjectHasNoAppConfig_DefaultAppConfigFileNameReturned()
 		{
 			CreateProjectWithMSBuildProject();
-			msbuildProject.FileName = @"d:\projects\MyProject\myproject.csproj";
+			msbuildProject.FileName = FileName.Create(@"d:\projects\MyProject\myproject.csproj");
 			
 			string fileName = project.GetAppConfigFileName();
 			
@@ -402,7 +403,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void GetAppConfigFileName_ProjectHasAppConfigInSubFolder_AppConfigFileNameReturned()
 		{
 			CreateProjectWithMSBuildProject();
-			msbuildProject.FileName = @"d:\projects\MyProject\myproject.csproj";
+			msbuildProject.FileName = FileName.Create(@"d:\projects\MyProject\myproject.csproj");
 			AddFileToMSBuildProject(@"SubFolder\app.config");
 			string fileName = project.GetAppConfigFileName();
 			
diff --git a/src/Main/Base/Test/ServiceReferences/ServiceReferencesFolderNodeTests.cs b/src/Main/Base/Test/ServiceReferences/ServiceReferencesFolderNodeTests.cs
index 61f38d8f45..0be3418839 100644
--- a/src/Main/Base/Test/ServiceReferences/ServiceReferencesFolderNodeTests.cs
+++ b/src/Main/Base/Test/ServiceReferences/ServiceReferencesFolderNodeTests.cs
@@ -3,6 +3,7 @@
 
 using System;
 using Gui.Pads.ProjectBrowser.TreeNodes;
+using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop.Project;
 using ICSharpCode.SharpDevelop.Tests.WebReferences;
 using NUnit.Framework;
@@ -41,7 +42,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void Directory_ProjectItemHasServiceReferenceDirectory_ReturnsFullPathToServiceReferencesDirectory()
 		{
 			CreateServiceReferenceProjectItem();
-			project.FileName = @"d:\projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"d:\projects\MyProject\MyProject.csproj");
 			projectItem.Include = @"Service References\";
 			CreateFolderNode();
 			
diff --git a/src/Main/Base/Test/ServiceReferences/ServiceReferencesProjectItemTests.cs b/src/Main/Base/Test/ServiceReferences/ServiceReferencesProjectItemTests.cs
index f630fea88e..008ad56783 100644
--- a/src/Main/Base/Test/ServiceReferences/ServiceReferencesProjectItemTests.cs
+++ b/src/Main/Base/Test/ServiceReferences/ServiceReferencesProjectItemTests.cs
@@ -2,6 +2,7 @@
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
 using System;
+using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop.Project;
 using ICSharpCode.SharpDevelop.Tests.WebReferences;
 using NUnit.Framework;
@@ -36,7 +37,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void Directory_ProjectItemIncludePathEndsWithForwardSlash_ReturnsFullPathOfServiceReferencesFolder()
 		{
 			CreateProjectItem();
-			project.FileName = @"C:\Projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"C:\Projects\MyProject\MyProject.csproj");
 			projectItem.Include = @"Service References\";
 			
 			string directory = projectItem.Directory;
@@ -48,7 +49,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void IsServiceReferencesFolder_FolderMatchesServiceReferencesFolder_ReturnsTrue()
 		{
 			CreateProjectItem();
-			project.FileName = @"C:\Projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"C:\Projects\MyProject\MyProject.csproj");
 			projectItem.Include = @"Service References\";
 			string folder = @"C:\Projects\MyProject\Service References";
 			
@@ -61,7 +62,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void IsServiceReferencesFolder_FolderDoesNotMatcheServiceReferencesFolder_ReturnsFalse()
 		{
 			CreateProjectItem();
-			project.FileName = @"C:\Projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"C:\Projects\MyProject\MyProject.csproj");
 			projectItem.Include = @"Service References\";
 			string folder = @"d:\projects\MyProject\Test";
 			
@@ -74,7 +75,7 @@ namespace ICSharpCode.SharpDevelop.Tests.ServiceReferences
 		public void IsServiceReferencesFolder_FolderMatchesServiceReferencesFolderButWithDifferentCase_ReturnsTrue()
 		{
 			CreateProjectItem();
-			project.FileName = @"C:\Projects\MyProject\MyProject.csproj";
+			project.FileName = FileName.Create(@"C:\Projects\MyProject\MyProject.csproj");
 			projectItem.Include = @"Service References\";
 			string folder = @"c:\projects\myproject\service references";
 			
diff --git a/src/Main/Base/Test/Utils/ProjectHelper.cs b/src/Main/Base/Test/Utils/ProjectHelper.cs
index e6c5eb4e13..bb3b3bc78e 100644
--- a/src/Main/Base/Test/Utils/ProjectHelper.cs
+++ b/src/Main/Base/Test/Utils/ProjectHelper.cs
@@ -17,7 +17,7 @@ namespace ICSharpCode.SharpDevelop.Tests.Utils
 		
 		public ProjectHelper(string fileName)
 		{
-			Project.Stub(p => p.FileName).Return(fileName);
+			Project.Stub(p => p.FileName).Return(FileName.Create(fileName));
 			
 			Project
 				.Stub(p => p.Items)
diff --git a/src/Main/Base/Test/WebReferences/DirectoryNodeFactoryTests.cs b/src/Main/Base/Test/WebReferences/DirectoryNodeFactoryTests.cs
index 43c12b2f72..74b6974522 100644
--- a/src/Main/Base/Test/WebReferences/DirectoryNodeFactoryTests.cs
+++ b/src/Main/Base/Test/WebReferences/DirectoryNodeFactoryTests.cs
@@ -1,6 +1,7 @@
 // Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
+using ICSharpCode.Core;
 using NUnit.Framework;
 using System;
 using System.IO;
@@ -24,7 +25,7 @@ namespace ICSharpCode.SharpDevelop.Tests.WebReferences
 		public void SetUpFixture()
 		{
 			MSBuildBasedProject project = WebReferenceTestHelper.CreateTestProject("C#");
-			project.FileName = Path.Combine(projectDirectory, "foo.csproj");
+			project.FileName = FileName.Create(Path.Combine(projectDirectory, "foo.csproj"));
 			project.AppDesignerFolder = "Properties";
 			
 			WebReferencesProjectItem webReferencesItem = new WebReferencesProjectItem(project);
diff --git a/src/Main/Base/Test/WebReferences/WebReferenceTestHelper.cs b/src/Main/Base/Test/WebReferences/WebReferenceTestHelper.cs
index 23b40be391..100abc4675 100644
--- a/src/Main/Base/Test/WebReferences/WebReferenceTestHelper.cs
+++ b/src/Main/Base/Test/WebReferences/WebReferenceTestHelper.cs
@@ -30,7 +30,7 @@ namespace ICSharpCode.SharpDevelop.Tests.WebReferences
 				: base(new ProjectCreateInformation {
 				       	Solution = new Solution(new MockProjectChangeWatcher()),
 				       	ProjectName = "TestProject",
-				       	OutputProjectFileName = "c:\\temp\\TestProject.csproj"
+				       	OutputProjectFileName = FileName.Create("c:\\temp\\TestProject.csproj")
 				       })
 			{
 				this.languageName = languageName;
diff --git a/src/Main/Base/Test/WebReferences/WebReferenceTests.cs b/src/Main/Base/Test/WebReferences/WebReferenceTests.cs
index cde4b601a3..5b72d94713 100644
--- a/src/Main/Base/Test/WebReferences/WebReferenceTests.cs
+++ b/src/Main/Base/Test/WebReferences/WebReferenceTests.cs
@@ -1,6 +1,7 @@
 // Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
+using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop;
 using ICSharpCode.SharpDevelop.Project;
 using NUnit.Framework;
@@ -39,7 +40,7 @@ namespace ICSharpCode.SharpDevelop.Tests.WebReferences
 		public void SetUpFixture()
 		{
 			project = WebReferenceTestHelper.CreateTestProject("C#");
-			project.FileName = "C:\\projects\\test\\foo.csproj";
+			project.FileName = FileName.Create("C:\\projects\\test\\foo.csproj");
 
 			protocol = new DiscoveryClientProtocol();
 			DiscoveryDocumentReference discoveryRef = new DiscoveryDocumentReference();
diff --git a/src/Main/Base/Test/WebReferences/WebReferencesProjectItemTests.cs b/src/Main/Base/Test/WebReferences/WebReferencesProjectItemTests.cs
index 74f5367067..d6ee5865ac 100644
--- a/src/Main/Base/Test/WebReferences/WebReferencesProjectItemTests.cs
+++ b/src/Main/Base/Test/WebReferences/WebReferencesProjectItemTests.cs
@@ -1,6 +1,7 @@
 // Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
+using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop.Gui;
 using ICSharpCode.SharpDevelop.Project;
 using NUnit.Framework;
@@ -30,7 +31,7 @@ namespace ICSharpCode.SharpDevelop.Tests.WebReferences
 		public void IsWebReferencesFolder_FolderMatchesWebReferencesProjectItemFolder_ReturnsTrue()
 		{
 			CreateProject();
-			project.FileName = @"C:\projects\test\foo.csproj";
+			project.FileName = FileName.Create(@"C:\projects\test\foo.csproj");
 			AddWebReferencesToProject(@"Web References\");
 			
 			bool result = WebReferencesProjectItem.IsWebReferencesFolder(project, @"C:\projects\test\Web References");
@@ -42,7 +43,7 @@ namespace ICSharpCode.SharpDevelop.Tests.WebReferences
 		public void IsWebReferencesFolder_FolderDoesNotMatchWebReferencesProjectItemFolder_ReturnsFalse()
 		{
 			CreateProject();
-			project.FileName = @"C:\projects\test\foo.csproj";
+			project.FileName = FileName.Create(@"C:\projects\test\foo.csproj");
 			AddWebReferencesToProject(@"Web References\");
 			
 			bool result = WebReferencesProjectItem.IsWebReferencesFolder(project, @"C:\projects\test\foo");
diff --git a/src/Main/SharpDevelop/Parser/ParserService.cs b/src/Main/SharpDevelop/Parser/ParserService.cs
index 6ea97deaee..7018a65673 100644
--- a/src/Main/SharpDevelop/Parser/ParserService.cs
+++ b/src/Main/SharpDevelop/Parser/ParserService.cs
@@ -45,8 +45,7 @@ namespace ICSharpCode.SharpDevelop.Parser
 					string addition;
 					if (e.OldUnresolvedFile == null) {
 						addition = " (new)";
-					} else
-			if (e.NewUnresolvedFile == null) {
+					} else if (e.NewUnresolvedFile == null) {
 						addition = " (removed)";
 					} else {
 						addition = " (updated)";